Rare blast of light reveals star's dramatic death by 'spaghettification'

Astronomers have recorded a rare glimpse of a star being shredded into thin streams of spaghetti-like material by a supermassive black hole.

An international research collaboration, including the University of Southampton postgraduate student Tomás E. Müller-Bravo, has reported the sighting of the closed ever observed example of the phenomenon known as a tidal disruption event (TDE).

The burst of light produced during the 'spaghettification' of a star is often obscured by dust and debris. Crucially, the AT 2019qiz TDE was found just a short time after the star was ripped apart, providing rich data that can increase the understanding of supermassive black holes and how matter behaves in extreme gravity environments.

Researchers from the Public ESO Spectroscopic Survey of Transient Objects group, known as ePESSTO+, have published their findings this week in the Monthly Notices of the Royal Astronomical Society.

Mr Müller-Bravo, of the Southampton Astronomy Group, says: "A TDE happens when a star orbits too close to a supermassive black hole and is pulled apart by its immense tidal force. Part of the disrupted star starts orbiting the black hole, while the rest is ejected.

"Due to its unprecedented proximity, this TDE was well monitored in the ultraviolet and optical ranges of the electromagnetic spectrum, but also observed in X-rays and radio wavelengths, producing a very rich dataset. From very early observations we were able to see behind the curtain of dust and debris, which allows us to have a better idea of the physical picture behind these events."

The AT 2019qiz event involved a star with roughly the same mass as our own Sun, just over 215 million light-years from Earth in a spiral galaxy in the constellation of Eridanus. Around half of the star's mass was lost to a black hole of over a million times its size.

Researchers carried out observations over a six-month period as the flare grew in luminosity and then faded away.

The collaboration gathered the data using telescopes from the European Southern Observatory (ESO) and other organisations around the world.

Mr Müller-Bravo is in charge of the data-reduction code for ePESSTO+ that transforms raw data from telescope images into ready-to-use data for the analysis. He performed observations using the New Technology Telescope (NTT) on ESO's La Silla observatory in Chile during the newly published research and supported the collaboration's analysis.